Process of producing yellow dyeings on cellulose esters or cellulose ethers



Patented June 19, 192.,

s'rss Fete-E.

ERICK FISCHER AND CARL ERICK M'OLLER, 0F HOCHST-ON-THE-MAIN, GERMANY, AS- SIGNORS TO GRASSELLI DYESTUFF CORPORATION, OF NEW YORK, N. Y., A COR- PORATION OF DELAWARE.

PROCESS OF PRODUCING YELLOW, DYEINGS ON CELLULOSE ESTERS OR CELLULOSE ETHEBS.

No Drawing. Application filed July 19, 1927, Serial No. 207,013, and in Germany July 29, 1926.

It is known to dye acetyl cellulose with dyestuif 4-benZene-azo-26-clinitrol-sulfomono-sulfonated nitro-diarylamines. These diphenylarnine of the formula: dyestuffs have, however, but a slight afiinity for the acetate silk so that they give only very light dyeings.

Furthermore it is known-that dyestuffs, obtainable by the act-ion of nitro-diazo compounds upon diphenylamine-sulfonic acid, or of nitrosulfodiazo compounds upon diphenylamine, produce deep dyeings on acetylcellulose. The value of all these dyestuffs, as far as yellow dyestuffs are concerned, is insignificant as they yield dyeings whichare I either phototrope or only moderately fast to light or acids.

According to the present invention all the above-named disadvantages are obviated by using for the dyeing monosulfonated nitroarylazodiarylamines containing at least one nitro group in the diarylamine complex. Such dyestufi's are obtained, for instance, by condensing nitroor dinitrochloro-benzenesulfonic acid with aminoaryl azo-dyestuffs, or by condensing nitroor dinitro-chlorobenz'enes with monosulfonated aminoazo dyestuifs. The finished dyestuffs may even contain some other groups such as, for instance, NH NI-LCH, or the like, OH, OCH and so on.

The following examples serve to illustrate our invention, but they are not intended to limit it thereto: 7

(1) 1 kg. of acetate silk is dyed in the usual manner for to ljhour at 60 C. to 70 C. in a dyebath containing 20 g. of the with or Without the addition of a salt, an acid, or'a protective coloid. The intense golden-yellow dyeing thus produced is disfastness. Furthermore the dyestuif is particularly valuable for the fact that it yields non-phototrope dyeings when combined with other dyestufi's so as to give for instance brown or green tints.

(2) 1 kg. of acetate silk is dyed in the manner indicated in Example 1 with 20 g. of the dyestufi': 4-benzene-azo-4J-nitro-2- sulfodiphenylamine. The yellow dyeing so obtained has likewise good fastness properties.

By the term cellulose ethers we include tinguished by its excellent properties as to v fonated arylazodiarylamines containing at least one nitro group stanchng 1n the diarylamine complex.

' 4. Cellulose materials dyed with 4-benzene-c azo-QtY-dinitroA-sulfodiphenylamine of the formula containing at least one nltro group standing in the diarylamine complex.

2. The process of producing yellow 'dyeings-on cellulose esters by dyeing the fiber with 4; benzene azo 2'6-'dinitro-4l'-sulfodiphenylamine of the formula:

3. Cellulose materials dyed with monosul- SOaH In testimony whereof, We aflix our signatures.

ERICH FISCHER. CARL ERICH MULLER. 

